Method of making hydrochloric acid



C, P. OWNSEND.

METHOD 0F MAKING HYDHOCHLORIC ACID.

APPLICATION F-ILEp MAR. 1, |920.

ELECTIJ'JHELEEGM CMPANY, 012V NEW Y'Qlt, E'. Y., A CORPOEATEN Specication ot Letters Patent.

Patented lliiay 2, 19%@ Anneation Elect March l, 192e. serial No. 362,125?.

Y chloric Acid, or which the following is a specification. Y

rzhis invention is a novel method of Inaking hydrochloric acid, including aqueous solutionsl thereof, by the direct union ot hydrogen and chlorin. A primary object of the invention is to provide a method whereby hydrogen and chlorin may be caused to unite in theoretical proportions in a system which is or may be closed in so far as any substantial or material gas exit is' concerned.

it is well known that chlorin may be burned 'in an atmosphere oi'. hydrogen, or that chlorin and hydrogen may be caused to unite with production of a iiame, the immediate product of the reaction being gaseous hydrochloric acid, HC1: and this operation is atv present employed in the commercial manufacture of hydrochloric acid, the gaseous hydrochloric acid being absorbedt'rom the elluent gases by means of water in any appropriate tourril or tower vor tourril and tower system. ln the commercial manufacture of hydrochloric acid by this method it is practically necessary to employ hydrogen in very material excess of the reacting proportions, since contamination of the acid product or pollution of the atmosphere by chlorin is thereby best avoided. i uch procedure is, however, obviously wasteful as regards consumption of hydrogen except as provision may be made for the return of excess hydrogen to the burner. Furthermore the chlorin employed is as a rule diluted toa greater or less extent by air or oxygen, which involves further losses ot' hydrogen by combination with oxygen, and further losses of hydrochloric. acid in the exit gases, or at least expensive extensions of the scrubber system for treating the exit gases, the volume of which is of course increased in proportion to the presence of nitrogen or other inert gases.

According tol the present invention,

chlorin and hydrogen, both of which should preferably be substantially undiluted, although they need not necessarily be dry,

are caused to unite in a system which is subi stantially or wholly closed to the escape oi' gas; 'the chlorin bein admitted to the system in a regulated anc substantially constant stream, Whereas the admission of hydrogen is so regulated and controlled as to maintain a substantially constant pressure in the system, which pressure may be either atmospheric or superor sub-atmospheric. Preterably a suitable pressure regulator provided in the system, and operates by controlling the inflow orn hydrogen from an external source.

rlhe accompanying drawing, which is diaof apparatus adapted :tor carrying the method into edect. A Referring to said drawing: i

10 indicates a burner which may be oi silica or other appropriate material, and which receives chlorin gas (preferably substantially pure chlorin evaporated from the liquid state) through a supply pipe 11 having a sensitive control valve and a metering device 12. In the preferred operating method the chlorin supply is maintained'as nearly constant as practicable, and accordingly the chlorin supply valve may be either automatically or manually controlled as may be desired.

Hydrogen is supplied to the burner 10 through main 13, in which is a metering device 14 and a control valve 15, the latter preferably of the automatic type and conulator serves, as Will be readily understood, to maintain a substantially constant pressure, Whether atmospheric or above or below atmospheric, throughout the system.

16 is a combustion chamber for the hydrogen-chlorin flame, and may also be of silica ware. The acid gas first traverses a cooling system 17, and passes thence tothe absorption system in which it is brought intocontact with water for the production of aqueous acid solutions. The absorption system will of course be designed in accordance with the acid concentration desired: for simplicity of illustration it is diagrammatically illustrated as comprising a packed absorption tower 18, the HC1 entering at the lower portion through conduit 19 while the Water is sprayed in at the top as indicated at 20. 'llhe tower is closed at the bottom by a sealin -well 21 having an overflow 22 for the finis ed acid. rll`he tower is also closed at the top and may carry a manometer or other pressure indicating device 23. The upper portion ot' the tower stands in direct connection through pipe 24 with the pressure-regulating gasometer 25.

26 is a hydrogen pressure chamber through which the absorbing water is introduced into the absorbing system 18. rllhis chamber communicates at its bottom with the top of the absorbing tower 18 through a watersealed pipe 27: at its upper portion it is connected by branch pipe 28 with the main hydrogen supply line 13, and by pipe 29 with a water injector 30. The latter receives its supply of water under pressure through valved pipe 31, and communicates through a branch pi e 32 and pipe 24 with the upper portion oi t e absorption tower 18.

rll`he system as above described may be operated as follows:

Hydrogen is first admitted through the Valve 15 and allowed to lill the system, displacing the air, whereupon the seals are filled and the system closed to access ot air, the hydrogen supply valve remaining o en until a. slight positive pressure is notedP at the manometer 23. rllhe water injector 30 is then started in operation to supply water to the absorbing tower, at the same time by its injector action, drawing hydrogen from the tower through the branch pipe 32 and :forcing it under slight presssure to the burner 10, through pipes 28 and 13, the flow of hydrogen bein in the direction indicated by the arrows. ure chlorin is then admitted in regulated and constant supply through the supply line 11, and the burner flame started in any convenient manner, for example by an electric igniter. The hydrogen is initially in relatively large excess as compared with the chlorin, thereby insuring complete combination of the latter and an acid free from uncombined' chlorin. rlhis acid gas with the accompanying excess of hydrogen passes through cooling coils 17 to the absorption tower 18, in which the hydrochloric acid is absorbed, the aqueous acid overilowing from the well at 22. T he hydrogen circulates continuously through the system in the manner already described. ln the meantime additional hydrogen is admitted to the system through the valve 15 in quantity just suiiicient to maintain the desired and established pressure within the system. lnasmuch as the amount of hydrogen required to maintain a constant ressure (whether positive or negative) wit in the system is the amount required to replace the hydrogen which has been withdrawn trom the system through combination with chlorin, it will be readily understood that in the continued operation ot the system, and

integr/ea the pressure within the system should be,

constantly maintained by the supply ot hydrogen in amount sumcient to replace that withdrawn from the system through combination with chlorin and removal of the resulting acid.

Any appropriate method may be employed tor controlling or increasing the conoentration of the acid: for example the acid eiluent or any portion thereof may be recirculated through the absorbing system; or the water may be re-circulated from the pressure chamber 26 through the injector 30, allowing only a limited overflow to t-he absorbing tower 18, this overflow regulated in accor ance with the concentration ofthe acid desired.

l claim 1. Method ot roducing hydrochloric acid comprising con ning a body of hydrogen in a substantially closed system; supplying chlorin .to the system at substantially constant rate and effecting it's combination with a portion of the hydrogen; withdrawing the resulting hydrochloric acid from the system;

and maintaining the desired pressure within4 the system by the regulated supply of hydrogen thereto. 'i

2. Method of producing hydrochloric acid comp-rising circulating a body of hydrogen through a substantially closed system; supplying chlorin to the system at substantially constant rate and eiecting its combination with a portion ot the hydrogen; withdrawing the resulting hydrochloric acid from the system; and maintaining the desired pressure within the system by the regulated supply ot hydrogen thereto.

3. Method of producing hydrochloric acid comprising conning a; body of hydrogen in a substantially closed system; supplying chlorin to the system at substantially constant rate and effecting its combination with a portion of the hydrogen; withdrawing the resulting hydrochloric acid from the system; and utilizing,the pressure wit-hinthe System to control automatically the supply of hydrogen thereto.

lin testimony whereof, li aiiix my signature.

CMNTUN PAUL TUWNSEND. 

